Loom stop-motion



Aug. 31, 1937. E. P. RocHELl-:AU

LOOM STOP MOTION Filed April 9, 1936 Patented Aug. 31, 1937 UNITED STATES PATENT OFFICE 7 Claims.

This invention relates to improvements in electrically-controlled stop-motions for looms and more particularly to a control unit including a switch and operating mechanism therefor.

Electrically-controlled stop-motions adapted to be operated by a fallen or misplaced harness frame to automatically arrest the operation of a loom have heretofore been employed in the weaving art; but such prior constructions have certain disadvantages in use. One disadvantage of such prior stop-motions results from the type of switch used which presents a serious re hazard due to sparking of the contacts in the lintladen atmosphere of a mill. As' a result, re underwriters have been opposed to the use of previous types of stop-motion control units. Another deiiciency results from the construction of the contacts which are spring-pressed and normally held in spaced relation byT an element of the harness-suspension means, thus causing considerable friction and wear. Still another deiiciency of such prior stop-motion control units results from their limitations las to use with a particular type of loom, thus requiring different designs for looms made by different manufacturers.

One of the objects of the present invention is to provide an electrically-controlled device for arresting the operation of the loom if one or more of the harness frames drops due to slackness or a break in the suspension straps; or should a harness frame become tilted or misalined from disarrangement of the suspension means. f

Another object of the invention is to provide an electric control unit for loom stop-motions incorporating a hermetically sealed switch enclosed within a housing to eliminate the possibility of nre hazard due to sparking.

Another object of the invention is to provide an operating mechanism for the control switch which is normally free from contact with the connections of the harness-suspension means to eliminate friction and wear on the parts.

Another object of the invention is to provide a self-contained control unit for electric stop-motions` for looms which is adjustable to adapt it to be used on various types of looms.

Still another object of the present invention is to provide an electric control unit of the type indicated which is simple `and compact in structure; economical to manufacture and assemble; and eflicient and positive in operation to perform its intended function.

Further objects of the improvement are set forth in the following specification which describes a preferred embodiment of the invention, by way of example, as illustrated by the accompanying drawing. In the drawing:

Fig. 1 is a perspective view of the operative parts of the stop-motion mechanism and the 5.

improved form of control unit therefor;

Fig. 2 is a side view of the control unit shown with the end plate removed to illustrate the normal position of the switch-operating bail with its crossbar spaced from the hari ess link and the switch in open-circuit position; and

Fig. 3 is a view similar to Fig. 2 showing the crossbar of the bail engaged by the link and the switch rocked to its closed-circuit position to operate the stop-motion of the loom.

Referring toFig. l of the drawing, a conventional type of harness frame 5 is illustrated as one of a series in a loom for mounting' the heddles 6 which support the-warp threads of the fabric to be woven. The harness frame 5 is suspended and operated by straps 'I and 8 connected at one end to the top of the frame and similar straps 9 and IIJ connected to the bottom of the frame at opposite sides thereof. The straps 1 a'nd 8 pass over fixed pulleys II and I2 and are connected to an oscillating lever I3 constituted as4 an element of the harness motion, while the opposite ends of the straps 9 and I0 are connected to a stirrup I4. The lever I3 is oscillated to raise and lower the harness frame 5 by means of a strap I5 connected between the lever I3 and one arm I6 of a jack-lever I'I. The harness suspension also includes straps I8 and I9 connected respectively to the stirrup I4 and the opposite arm 20 of the jack-lever II. The straps I8 and I9 extend downwardly around xed pulleys 2i and 22 at the bottom of the loom frame and are connected together by a link or stirrup wire 23 positioned wholly between the pulleys. The harness straps thus form a closed loop, being maintained 40 taut to positively control the movement and position of the harness frame 5 as the jack-lever I1 is rocked by the harness motion which may be of any usual type. If the harness straps become slack or broken the harness frame 5 will drop 45 or become misplaced so that it cannot vproperly shift the Warp threads to Aform the shed, thereby causing a smash which breaks the threads and damages the fabric being woven. Under such conditions the loom must be stopped and the 0 break repaired.

As diagrammatically illustrated in Fig. 1, a well-known type of automatically-operated stopmotion is provided in the loom, including a rock- 55 leverv 28 pivotally mounted ona xed shaft 29 and having a control-rod 30 connected to its lower end. A dagger 3| is pivotally mounted on the upper end of the lever 28 to be held in eithcr a lowered inoperative or raised operative posi- 5 tion by an arm 32 and connecting link 33. The arm 32 is operated to raise the dagger 3| by an electromagnet, not herein shown, contained in a box or casing 34. When the dagger 3| is raised by energizing the electromagnet it is engaged by a bunter on the lay or other going part of the loom, not shown, to rock the lever 28. The rocking motion of the lever 28 is transmitted through the control-rod 30 to operate a clutch or other driving connection to stop the loom.

The electromagnet 34 of the stop-motion is energized when the harness suspension becomes slack or any one of its connections is broken by the improved control unit constituting the subject-matter of the present invention. In the present illustrated embodiment of the invention the control unit is supported by a U-shaped bracket 36 having its crossbar below and extending at right-angles to the link 23 ofthe harness suspension; it being understood that the unit is 25 adapted to be operated by any one or more of a plurality of links for the whole series of harness frames used in the loom. The crossbar of the bracket 36 is fastened to the iloor or any other suitable support by bolts or screws 31 with its angular ends projecting upwardly on opposite sides of the wire link 23 to form stanchions 38. 'Ihe stanchions 38 are drilled or otherwiseY provided with a series of alined bearing apertures 39 for pivotally mounting a bail 40 at vdifferent heights above the crossbar of the bracket. The bail 40 is preferably made from a length of wire or rod bent to form a crank-arm having a crossbar 4| and angularly-extending legs'42 and 43, with portions of the legs formed to provide 40 gudgeons or trunnions for pivotally mounting the bail in one of the pairs of alined bearing apertures 39. As herein illustrated, the leg 42 is oifset intermediate its ends to form a trunnion 44 and then bent at right-angles to provide a lever 45 or arm 45; while the end of the leg 43 is bent to form a trunnion 46 in axial alinement with the trunnion 44. Although the arm 45 is herein shown as projecting from the trunnion 44 in the opposite direction from that of the leg 42 it will be understood that the arm may have other angular relations with respect thereto, or may be formed as a separate element attached to the bail. .A box-like casing 41 is bolted or otherwise secured to the stanchion 38 through which the trunnion 44 of the leg 42 of the bail 40 extends. As herein illustrated, the casing 41 encloses the arm 45 of the bail 40 and has an elongated opening 48 opposite the bearing apertures 39 to provide for vertical adjustment of the bail, the side of the casing opposite the stanchion 38 being open to permit such adjustment. When the control unit is initially applied to the loom the bail 40 is mounted in one of the pairs of alined bearing apertures39 in the stanchions 38 to position G5 its crossbar 4| closely adjacent the links 23 of the harness suspension. The bail 40 is normally rocked to an inclined position by an adjustable counterweight 49 on the arm 45, its rocking movement beingA limited by an adjustable stop 56 in the form of a crank for engaging the arm. The stop 50 is attached to the wall of the casing 41 by a screw 5| which permits adjustment for different types of looms so that the crossbar 4| 75 of the bail 40 may be normally positioned closely adjacent the links 23 while out of actual contact therewith to prevent friction and wear.

A hermetically sealed switch 52 of the tilting contact type is mounted on the arm 45, thereby eliminating any possibility of a re hazard due to sparking. Although the switch 52 may take any of a variety of forms well known in the art as comprising a gravity-responsive element for closing the contacts when the switch is tilted, preferably it is of the type embodying an enclosing envelope or glass tube containing a pair of' spaced contacts 53 and 54 and a globule oi.' mercury 55 for bridging the contacts. 'I'he switch 52 may be mounted on the arm 45 by any suitable means, herein shown as comprising metal clips 56 embracing the arm and envelope. 'I'he upper spaced ends of the clips 56 are drawn together in binding engagement by means oi.' screws 51 to rigidly hold the switch in position on the arm 45. 'I'he contacts 53 and 54 are electrically connected to suitable binding posts 53 and 59 on the casing 41 by means of flexible conductors 60 and 6|. Exteriorly of the casing 41 the binding post 58 is connected to the windings of the electromagnet in the casing 34 and the post 53 is grounded in the loom frame, as indicated at 10 in Fig. 1, by means of lead wires 62 and 63. Although not herein shown it will be understood that the opposite end oi' the electromagnet coil is connected with a source of current by a lead wire 54 which completes the circuit through the ground.

The control unit is preferably protected by an enclosing structure including end plates 65 and 66 secured to brackets 61 bolted to the iioor, and a cover plate 68 supported therefrom. The end plate 65 is preferably arranged to close the open side of the housing 41 and together with the opposite end plate 66 and cover plate 68 prevent the accumulation of dust and lint which might prevent the proper rocking movement of the bail 40 to operate the switch 52. 'I'he construction and arrangement of the device having now been described, its mode of operation is explained as follows.

In applying the control unit to any type of loom the U-shaped bracket 36 with the casing 41 attached thereto is bolted to the floor or other support below the series of links 23, only one being herein shown. The bail 40 is then mounted on the bracket 36 in one of the pairs of alined bearing apertures 39 so that its crossbar 4| will be located closely adjacent the links 23 when tilted upwardly by the counterweight 43 on the arm 45; the series of alined bearing apertures permitting adjustment of the bail vertically so that the unit is adapted for use with all types of looms. The crank-arm stop 50 on the side of the housing 41 is adjusted by loosening the screw 5| to position the crossbar 4| of the bail .40 closely adjacent the links 23 but out of actual contact therewith, as illustrated in Fig. 2. In this normal operating position of the bail 40 the switch 52 is tilted to an open-circuit position which maintains the electromagnet of the loom stopmotion deenergized and the dagger 3l depressed to its inoperative position. v

With power applied to the loom the jacklevers l1 are rocked in timed relation with the throw of the shuttle by the picker-sticks and the beat-up of the lay to raise and lower the several harness frames 5 and shift the heddles 6 to form the shed. As each jack-lever I1 is thus rocked the strap |5 causes the oscillating lever I3 to be rocked which, in turn, raises and lowers the hari 8. During the rising and falling movement of the the control unit of the present invention may be.

harness frames 5 the links 23 reciprocate in a horizontal plane unrestrained by any frictional contact. Theloom continues to operate until the harness suspension becomes slack or is broken at any connection, at which time the link 23 will engage the crossbar 4I of the bail 40. Due to the sensitive balance of the bail the weight of the link 23 will cause the bail and arm 45 to be rocked to the position shown in Fig. 3. The mercury 55 or other gravity-responsive element of the switch 52 then closes the circuit between the contacts 53 and 54 to energize the electromagnet. The magnet being energized raises the arm 32 to lift the dagger 3| which is then engaged by a reciprocating bunter on the lay or other going part of the loom. Engagement of the dagger 3l by the bunter causes the lever 28 to be rocked about its pivot 29 to move the control-rod 30 to stop the loom. The slack or broken harness suspension is thus immediately called to the operators attention so that it may be repaired before the occurrence of a smash due to improper opening of the shed. After the harness suspension has been repaired the bail 4l) is automatically rocked to its inoperative position shown in Fig. 2 by the counterweight 49 and the switch 52 tilted to open-circuit position.

It will be understood that the present control unit may be used for all of the harness frames 5 of the loom with a single switch 52 connected in circuit with the electromagnet which operates the stop-motion. It will also be understood that used with other types 'of harness-suspension means than that herein shown and may control any form of electrically-operated stop-motion. the present type being shown merely for purposes of illustration.

It is also noted that the device is adapted to operate automatically, not only upon the occurrence of the dropping of a harness frame, but whenever a harness frame becomes misalined or tilted due to breakage or slackness in one of its hold-down straps.

It will be observed from the foregoing that my invention provides a novel form of control unit for electrically-operated stop-motions which eliminates any possibility of a fire hazard; which permits the unimpeded operation of the harness motion without friction or wear; and which is adjustable for use on all types of looms. It will also be observed that the control mechanism is of very simple and compact construction adapted to be economically manufactured and assembled and positive in its operation to control the loom.

While one preferred embodiment of the invention is herein illustrated and described it will be apparent that various modications may be made in the structure and arrangement of the parts of the device which would fall within the spirit or scope of the invention. Therefore, without limiting myself in this respect, I claim:

l. In a stop mechanism for looms, a harness frame, suspension means for operating the frame v including a link, a lever, a hermetically sealed becomes slack or broken to rock the switch .to circuit-closing position.

2. In a stop mechanism for looms, a harness frame, suspension means for operating the frame including a link, a pivotally mounted bail havinga crossbar extending parallel to the pivotal axis thereof and positioned below the link, a hermetically sealed switch mounted on said bail and including a gravity-operated element for opening or closing the contacts when the bail is tilted. means for normally rocking the bail to maintain the switch in open-circuit position, and a stop for limiting the movement of the bail to position its crossbar closely adjacent while out of contact with the link, the crossbar of said bail being engaged by the link when the harness-suspension means becomes slack or broken to rock the switch to circuit-closing position.

3. In a stop mechanism for looms, a harness frame, suspension means for operating the frame including a link, a bail comprising a crossbar with angularly extending legs at its ends, one of the legs oi' the bail being offset to form a pivot and extended in an arm and the opposite leg being formed with a pivot axially alined with the pivot on the first leg, a tilting liquid-contact switch mounted on the extended arm of the bail, and means for rocking the bail to normally maintain the switch in open-circuit position, the crossbar ofsaid bail being engaged by the link when the harness-suspension means becomes slack or broken to rock the switch to closed-circuit position.

4. In a stop mechanism for looms, a harness frame, suspension means for operating the frame including a llink, a bracket mounted below the link and having opposed stanchions at opposite sides of the link, a bail having its opposite ends pivotally mounted on the bracket,'means for vertically adjusting the pivots of the bail on the stanchions of the bracket, means for normally rocking the bail about its pivot in one direction, an adjustable stop for limiting the movement of the bail to located its crossbar adjacent the link, and a tilting liquid-contact switch on the bail normally heldin open-circuit position, said bail being adapted to be rocked about its pivot by the link when the harness-suspension means becomes slack or broken to thereby tilt the switch to closed-circuit position.

5. In a stop mechanism for looms, a harness frame, suspension means for operating the frame including a link, a bracket positioned below the link and having a series of alined bearing apertures at different heights, a bail adapted to be pivotally mounted in the different pairs of alined bearing apertures in the bracket, means for normally rocking the bail to position its crossbar closely adjacent the link, and a mercury switch carried by the bail and normally heldin open-circuit position, said link adapted to engage the bail to rock the switch to closed-circuit position when the harness-suspension means becomes slack or broken.

6. In a stop mechanism for looms, a harness frame, suspension means for operating the frame including a link, a bracket below the link, a bail having a crossbar and trunnions at the ends thereof for pivotally mounting the bail on thebracket to swing about an axis parallel to and offset from the crossbar, a mercury switch mounted on the bail, adjustable means f for rocking the bail to position its crossbar adjacent the link while maintaining the switch in open-circuited position, and a housing enclosing the bail and switch, said link adapted to rock the bail to tilt the switch to closed-circuit position when the harness-suspension means becomes slack or is broken.

'7. In combination with the electrical stopmo tion of a loom. an electrical circuit for said stopmotion, suspension means for the harness frames of the loom, links connecting said suspension means, a U-shaped bail having a crossbar and legs extending angularly from the crossbar, the

10 ends of the opposite legs being oilset in parallel relation to the crossbar to form trunnions for pivotally mounting the bail to position the crossbar below said links, and a gravity-operated switch on the bail connected in circuit with the electrical stop-motion of the loom and adapted t0 be tilted by rocking the bail about its pivotal axis, said bail adapted to be engaged by a link in the harness-suspension means due to slackness or breakage therein whereby to tilt the switch to close the electrical circuit.

EMILE P. ROCHELEAU. 

